Imaging apparatus

ABSTRACT

A imaging apparatus includes: a display module; a dust-proof plate arranged on an observer side of the display module and configured to substantially seal a surface of the display module; an eyepiece lens arranged on the observer side of the dust-proof plate and movable in an optical axis direction; and a cover member retaining the dust-proof plate and the eyepiece lens, wherein the cover member has an opening for removing foreign matter adhering to the surface of the dust-proof plate opposed to the eyepiece lens and to the surface of the eyepiece lens opposed to the dust-proof plate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus, and, inparticular, to an imaging apparatus equipped with a viewfinder.

2. Description of the Related Art

Conventionally, the viewfinder of an imaging apparatus displays an imageon a liquid crystal display unit based on a video signal duringshooting. And, the image displayed on the liquid crystal display unit isenlarged at an eyepiece lens.

However, any foreign matter such as dust adhering to the interior of theviewfinder hinders the observation of the image. In view of this, as isknown in the art, a dust-proof glass is provided between the eyepiecelens and the eyepiece opening to seal up the interior of the viewfinder.Further, Japanese Patent Application Laid-Open No. 5-68189 discusses aconstruction in which the dust-proof glass is arranged in an inclinedstate so that the external light may not be reflected by the dust-proofglass.

However, in the construction discussed in Japanese Patent ApplicationLaid-Open No. 5-68189, in which the dust-proof glass is arranged in aninclined state between the eyepiece lens and the eyepiece opening, it isnecessary to provide space, resulting in an increase in the size of theviewfinder. On the other hand, in the case where the dust-proof glass isarranged without being inclined, it is necessary for the surface of thedust-proof glass to be provided with coating for preventing reflection,resulting in an increase in man-hours and cost.

It might be possible to adopt a structure in which the interior of theviewfinder is not completely sealed and in which the interior of theviewfinder is cleaned by a blower as appropriate. However, a displaymodule arranged inside the viewfinder is very subject to fracture, andthere is danger of the display module suffering damage by the blowerduring cleaning or the like.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, an imaging apparatusincludes: a display module; a dust-proof plate arranged on an observerside of the display module and configured to substantially seal asurface of the display module; an eyepiece lens arranged on the observerside of the dust-proof plate and movable in an optical axis direction;and a cover member retaining the dust-proof plate and the eyepiece lens,wherein the cover member has an opening for removing foreign matteradhering to the surface of the dust-proof plate opposed to the eyepiecelens and to the surface of the eyepiece lens opposed to the dust-proofplate.

According to the present invention, it is possible to protect thedisplay module arranged inside the viewfinder while adopting a structurenot requiring complete sealing-up of the interior of the viewfinder ofthe imaging apparatus and allowing cleaning of the interior of theviewfinder by a blower.

Further features and aspects of the present invention will becomeapparent from the following detailed description of exemplaryembodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate exemplary embodiments, features,and aspects of the invention and, together with the description, serveto explain the principles of the invention.

FIG. 1 is an external perspective view of a viewfinder.

FIG. 2 is an exploded perspective view of the viewfinder.

FIG. 3 is an exploded perspective view of a viewfinder assembly.

FIG. 4 is an exploded perspective view of a display unit portion.

FIG. 5 is a sectional view illustrating the structure of a displaymodule.

FIG. 6 is a diagram, as seen from the front side of a dust-proof plate,illustrating how the dust-proof plate is incorporated into a covermember.

FIG. 7 is a perspective view illustrating how the display module ismounted to a display module holder.

FIG. 8 is a diagram, as seen from the front side of the dust-proofplate, illustrating how the dust-proof plate, the display module holder,and the display module are incorporated into the cover member.

FIG. 9 is a diagram illustrating how a component integrating an elasticmember and a lid member is mounted to the cover member.

FIGS. 10A and 10B are external perspective views of an eyepiece lensunit portion.

FIG. 11 is an exploded perspective view of the eyepiece lens unitportion.

FIGS. 12A, 12B, and 12C are main portion perspective views illustratingthe eyepiece lens unit portion as assembled.

FIGS. 13A, 13B, and 13C are perspective views illustrating how a mask isarranged between a second-unit eyepiece lens and a third-unit eyepiecelens.

FIG. 14 is a sectional view of the eyepiece lens unit portion.

FIG. 15 is a sectional view illustrating how the viewfinder assembly, anupper cover, and a lower cover are combined with each other.

FIG. 16 is an external perspective view of a video camera constitutingan example of an imaging apparatus according to an exemplary embodimentof the present invention.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the inventionwill be described in detail below with reference to the drawings.

FIG. 16 is an external perspective view of a video camera constitutingan example of an imaging apparatus to which the present invention isapplied. As illustrated in FIG. 16, the video camera is equipped with aviewfinder 1.

FIG. 1 is an external perspective view of the viewfinder 1. Asillustrated in FIGS. 1 and 16, in the present exemplary embodiment, theupper, lower, right-hand, and left-hand sides of the viewfinder 1 asseen from the observer side will be defined as the upper, lower,right-hand, and left-hand sides of the imaging apparatus.

FIG. 2 is an exploded perspective view of the viewfinder 1.

The viewfinder 1 is constructed such that a viewfinder assembly 5 iscovered with an upper cover 2, a lower cover 3, and an eyecup 4 that isattachable/detachable by the observer. An opening 2 a is formed in theupper cover 2. The lower cover 3 has an opening 3 a through which aneyepiece lens unit portion 7 is exposed.

FIG. 3 is an exploded perspective view of the viewfinder assembly 5. Theviewfinder assembly 5 includes a display unit portion 6, an eyepiecelens unit portion 7, and a cover member 8. The cover member 8 retainsthe display unit portion 6 and the eyepiece lens unit portion 7. Thedisplay unit portion 6 corresponds to a display unit integrating adisplay module 9 and a dust-proof plate 11, and the eyepiece lens unitportion 7 corresponds to an eyepiece lens unit integrating a pluralityof lenses with each other.

A diopter adjustment knob 33 is formed to protrudes under the eyepiecelens unit portion 7, allowing diopter adjustment as described below. Anopening 8 b is formed in the upper portion of the cover member 8.

FIG. 4 is an exploded perspective view of the display unit portion 6.The display unit portion 6 includes the display module 9, a displaymodule holder 10, the dust-proof plate 11, an elastic member 12, and alid member 13. The display module 9 displays an image based on a videosignal during shooting. The display module holder 10 retains the displaymodule 9. The dust-proof plate 11 is provided behind the display module9, and protects the display module 9 from dust or the like. The elasticmember 12 is held in a compressed state between the lid member 13 andthe cover member 8, thereby urging the display module 9, the displaymodule holder 10, and the dust-proof plate 11 toward the cover member 8.

FIG. 5 is a sectional view illustrating the structure of the displaymodule 9. In the present exemplary embodiment, the display module 9 usesa reflection type liquid crystal display; it reflects light emitted froma light source 14 by a film surface 15, and irradiates an image displaysurface 16 to obtain a light quantity, thereby displaying an image.

Next, the sealing structure of the display unit portion 6 will beillustrated with reference to FIGS. 4, 6, 7, and 8.

In the case where foreign matter such as dust has entered the displaymodule 9, such dust can be visually recognized by the user using theviewfinder, which makes the displayed image rather hard to observe.Thus, it is necessary to equip dust-proof so that dust does not adhereto the display module 9. As illustrated in FIG. 4, in the presentexemplary embodiment, the members are successively urged from the frontside toward the rear side in the optical axis direction, whereby thedisplay unit portion 6 is sealed, or at least substantially sealed.Description is made according to an order of assembling the display unitportion 6.

FIG. 6 is a diagram, as seen from the front side of the dust-proof plate11, illustrating the state where the dust-proof plate 11 is incorporatedinto the cover member 8. The dust-proof plate 11 has a cutout portion17, which is engaged with a protrusion portion 18 of the cover member 8solely at the correct position. The dust-proof plate 11 is incorporatedinto the cover member 8 in the direction as indicated in FIG. 6, and iscaused to abut on an inner wall 8 a of the cover member 8. Thedust-proof plate 11 cannot be incorporated into the cover member 8 inany other direction than that indicated in FIG. 6.

The dust-proof plate 11 is set in position with respect to the covermember 8 by causing the upper, lower, right-hand, and left-hand sides ofthe dust-proof plate 11 to abut on a positioning rib 19 formed on thecover member 8.

Next, the display module holder 10 and the display module 9 areincorporated in that order. As illustrated in FIG. 7, the display module9 has cutout portions 20 for positioning, and the display module holder10 has a positioning rib 21 and an elastic urging rib 22. The cutoutportions 20 of the display module 9 are respectively engaged with thepositioning rib 21 and the urging rib 22 of the display module holder10, whereby the display module 9 is set in position with respect to thedisplay module holder 10. The display module 9 is urged to one side withrespect to the display module holder 10, whereby variation in positiondue to play is mitigated.

FIG. 8 is a diagram, as seen from the front side of the dust-proof plate11, illustrating a state where the dust-proof plate 11, the displaymodule holder 10, and the display module 9 are incorporated.Specifically, the diagram illustrates a state, starting from the stateof FIG. 6, where the display module holder 10 and the display module 9are incorporated into the cover member 8. As illustrated in FIG. 8,sliding portions 23 are formed on the cover member 8; by causing thesliding portions 23 to slide, it is possible for the display moduleholder 10 to be smoothly incorporated into the cover member 8.

After the display module holder 10 and the display module 9 isincorporated into the cover member 8, the elastic member 12 and the lidmember 13 are integrally mounted to the cover member 8. FIG. 9 is adiagram illustrating a state where a component integrating the elasticmember 12 and the lid member 13 is mounted to the cover member 8. Asillustrated in FIG. 9, a claw 24 formed on the cover member 8 and a hook25 formed on the lid member 13 are engaged with each other, whereby thelid member 13 is mounted to the cover member 8. In this case, theelastic member 12 is held between the cover member 8 and the lid member13 in a compressed state. Accordingly, the elastic member 12 urges thedisplay module 9, the display module holder 10, and the dust-proof plate11 toward the inner wall 8 a of the cover member 8. As a result, therear surface of the dust-proof plate 11 is brought into intimate contactwith the inner wall 8 a of the cover member 8, whereby the space fromthe dust-proof plate 11 to the display module 9 is sealed.

FIGS. 10A and 10B are external perspective views of the eyepiece lensunit portion 7. The eyepiece lens unit portion 7 enlarges a finder imagedisplayed on the display module 9. By moving the eyepiece lens unitportion 7 in the optical axis direction, the position of the eyepiecelens unit portion 7 with respect to the display module 9 is varied,whereby it is possible to make a diopter adjustment in conformity withthe eyesight of the observer. In other words, the eyepiece lens unitportion 7 corresponds to an eyepiece lens, which is arranged on theobserver side of the dust-proof plate 11 to be movable in the opticalaxis direction.

A boss 7 a arranged on the lower surface of the eyepiece lens unitportion 7 illustrated in FIG. 10A connects with a diopter adjustmentknob 33. As a result, through the operation of the diopter adjustmentknob 33 by the observer, the eyepiece lens unit portion 7 moves in theoptical axis direction, and its position with respect to the displaymodule 9 is varied. In other words, through the operation of the diopteradjustment knob 33 by the observer, it is possible to make diopteradjustment.

FIG. 11 is an exploded perspective view of the eyepiece lens unitportion 7. The eyepiece lens unit portion 7 accommodates a box-like lensholder 26, a first-unit eyepiece lens 27, a second-unit eyepiece lens28, and a third-unit eyepiece lens 29, which are covered up by a holdercover 31. Further, between the second-unit eyepiece lens 28 and thethird-unit eyepiece lens 29, a mask 32 for shielding the display module9 against unnecessary light is arranged.

Next, a method of setting the first-unit eyepiece lens 27, thesecond-unit eyepiece lens 28, and the third-unit eyepiece lens 29 inposition with respect to the lens holder 26 will be illustrated. Thefirst-unit eyepiece lens 27 has convex configurations on both sides. Thesecond-unit eyepiece lens 28 has concave configurations on both sides.The third-unit eyepiece lens 29 has convex configurations on both sides.

FIG. 14 is a sectional view of the eyepiece lens unit portion 7; light30 is emitted from the display module 9. As illustrated in FIG. 14, therequisite range for allowing the requisite light for observing the imagedisplayed on the display module 9 to enter, is larger in the first-uniteyepiece lens 27 and the third-unit eyepiece lens 29 than in thesecond-unit eyepiece lens 28. Thus, the outer size of the first-uniteyepiece lens 27 and of the third-unit eyepiece lens 29 needs to belarger than the outer size of the second eyepiece lens 28.

Next, the configuration of the eyepiece lens will be described. FIGS.12A through 12C are main portion perspective views illustrating theeyepiece lens unit portion 7 as assembled. As illustrated in FIG. 12A,insertion is effected such that ribs 27 a formed at the four corners ofthe first-unit eyepiece lens 27 are engaged with ribs 28 a formed at thefour corners of the second-unit eyepiece lens 28, which is one sizesmaller. As a result, the first-unit eyepiece lens 27 and thesecond-unit eyepiece lens 28 are set in position. As illustrated in FIG.12C, the third-unit eyepiece lens 29 is also inserted to be engaged withthe second-unit eyepiece lens 28, whereby the second-unit eyepiece lens28 and the third-unit eyepiece lens 29 are set in position. Further, byribs 29 a provided in the outer periphery of the third-unit eyepiecelens 29, the optical axis center of the third-unit eyepiece lens 29 isset in position with respect to the lens holder 26. As a result, theoptical axis centers of the first-unit eyepiece lens 27, the second-uniteyepiece lens 28, and the third-unit eyepiece lens 29 can be accuratelymatched with the field angle center of the display module 9.

In its normal uses, the viewfinder 1 is scarcely used upside down, sothat, in the present exemplary embodiment, the effect of thegravitational force is taken into account, and the upper and lowerportions of the second-unit eyepiece lens 28 are not in perfect symmetrywith respect to the optical axis center. Further, the shape of frontsurface and rear surface of the lens are different from each other withrespect to the second-unit eyepiece lens 28. In addition, the first-uniteyepiece lens 27 and the second-unit eyepiece lens 28 has similar shapeto each other. Thus, as illustrated in FIG. 12B, to prevent erroneousassembly, the second-unit eyepiece lens 28 has a protrusion 28 b, andthe first-unit eyepiece lens 27 has a recess 27 b. As a result, onlywhen the first-unit eyepiece lens 27 and the second-unit eyepiece lens28 are combined in the correct orientation, the protrusion 28 b of thesecond-unit eyepiece lens 28 is engaged with the recess 27 b of thefirst-unit eyepiece lens 27.

The third-unit eyepiece lens 29 is provided with no such configurationas described above. This helps to prevent erroneous assembly. Morespecifically, if the first-unit eyepiece lens 27 and the third-uniteyepiece lens 29 are mistaken for the other, the second-unit eyepiecelens 28 cannot be incorporated. Further, if the second-unit eyepiecelens 28 is incorporated in a horizontally opposite direction, itinterferes with the first-unit eyepiece lens 27. Further, if an attemptis made to incorporate the second-unit eyepiece lens 28 upside down, thethird-unit eyepiece lens 29 cannot be incorporated.

Further, the first-unit eyepiece lens 27, the second-unit eyepiece lens28, and the third-unit eyepiece lens 29 are set in position in theoptical axis direction by being held between the lens holder 26 and theholder cover 31. In the present exemplary embodiment, the holder cover31 includes an arm 31 a charging each eyepiece lens in the direction ofthe display unit portion 6; by incorporating the holder cover 31, anyplay in the optical axis direction of the eyepiece lenses is eliminated,so that there is no fear of the eyepiece lenses being toppled over.

FIGS. 13A through 13C are perspective views illustrating a state wherethe mask 32 is arranged between the second-unit eyepiece lens 28 and thethird-unit eyepiece lens 29. As illustrated in FIG. 14, the light 30 isnarrowed down by the second-unit eyepiece lens 28, so that the requisitediameter of the second-unit eyepiece lens 28 is smaller than that of thefirst-unit eyepiece lens 27 and the third-unit eyepiece lens 29.However, since the eyepiece lens unit portion 7 may be formed as arectangular parallelepiped, a gap is generated around the second-uniteyepiece lens 28. Thus, there is a fear of an adverse effect ofunnecessary light, such as the light allowed to directly enter thethird-unit eyepiece lens 29 from the first-unit eyepiece lens 27 withoutpassing by way of the second-unit eyepiece lens 28. In the presentexemplary embodiment, to avoid such an adverse effect, the mask 32 isarranged between the second-unit eyepiece lens 28 and the third-uniteyepiece lens 29. The mask 32 is arranged in the extension of the lenssurface of the second-unit eyepiece lens 28, and has an opening throughwhich the light 30 passes.

As illustrated in FIG. 13B, the mask 32 has holes 32 a at positionscorresponding to the ribs 28 a formed on the second-unit eyepiece lens28. By arranging the mask 32 with respect to the second-unit eyepiecelens 28 such that the ribs 28 a of the second-unit eyepiece lens 28 areinserted into the holes 32 a, positioning is effected between the mask32 and the second-unit eyepiece lens 28. Further, as illustrated in FIG.13C, the mask 32 is fixed in position in the optical axis direction bybeing held between the ribs 27 a of the first-unit eyepiece lens 27 andthe ribs 29 a of the third-unit eyepiece lens 29.

Further, as illustrated in FIG. 14, to restrict the unnecessary lightallowed to enter the first-unit eyepiece lens 27, a mask portion 26 b isformed on the viewfinder panel surface side of the lens holder 26. Asillustrated in FIG. 10A, in the present exemplary embodiment, the maskportion 26 b is formed by making, from under the lens holder 26, a holebetween the mask portion 26 b and the first-unit eyepiece lens 27retaining surface. Thus, while preventing intrusion of dust into theeyepiece lens unit portion 7, there may be no need to form the maskportion as a separate member, which means there may be no increase inthe number of components.

Owing to the above construction, the eyepiece lens unit portion 7 allowsthe optical axis centers of the first-unit eyepiece lens 27, thesecond-unit eyepiece lens 28, and the third-unit eyepiece lens 29 to beaccurately matched with the screen center of the display module 9. As aresult, it is possible to secure a satisfactory optical performance, toprevent intrusion of dust into the intervals between the eyepiecelenses, and to achieve an improvement in terms of visibility through areduction in the effect of unnecessary light.

Owing to the above construction, the display unit portion 6 and theeyepiece lens unit portion 7 are made dust-proof by being sealed in therespective units. However, the rear surface of the dust-proof plate 11,the front surface of the first-unit eyepiece lens 27, and the rearsurface of the third-unit eyepiece lens 29 are not sealed, and there isa fear of dust being allowed to adhere thereto.

FIG. 15 is a sectional view illustrating a state where the viewfinderassembly 5, the upper cover 2, and the lower cover 3 are combined witheach other. The opening 8 b formed in the upper portion of the covermember 8 serves to allow insertion of a blower to clean the rear surfaceof the dust-proof plate 11 and the front surface of the first-uniteyepiece lens 27. Specifically, the opening 8 b corresponds to theopening to remove foreign matter adhering to the surface of thedust-proof plate 11 opposed to the eyepiece lens unit portion 7 and tothe surface of the front eyepiece lens unit portion 7 opposed to thedust-proof plate 11.

As illustrated in FIG. 15, the opening 2 a of the upper cover 2 and theopening 8 b of the cover member 8 are matched with each other in thelongitudinal direction of the viewfinder 1. Thus, by inserting thedistal end of a blower through the opening 2 a of the upper cover 2, thedistal end of the blower enters the opening 8 b of the cover member 8;alternatively, gas ejected from the distal end of the blower enters theopening 8 b of the cover member 8. This helps to clean the rear surfaceof the dust-proof plate 11 and the front surface of the first-uniteyepiece lens 27.

In this case, the space from the dust-proof plate 11 to the displaymodule 9 is sealed, so that the distal end of the blower does not comeinto contact with the display module 9, nor does the gas ejected fromthe distal end of the blower directly damage the display module 9.

As illustrated in FIG. 1, by attaching an eyecup 4, the opening 2 a ofthe upper cover 2 and the opening 8 b of the cover member 8 are coveredwith the eyecup 4, whereby the opening 2 a and the opening 8 b isprevented from entering of a dust.

As illustrated in FIG. 15, the rear surface of the third-unit eyepiecelens 29 is exposed through the opening 3 a, so that it is possible toclean the rear surface of the third-unit eyepiece lens 29 through theopening 3 a.

As illustrated above, in the present exemplary embodiment, the spacefrom the dust-proof plate 11 to the display module 9 is formed as asealed space, whereas the space in which the eyepiece lens unit portion7 moves in the optical axis direction is formed as an open space. And,the cover member 8 has the opening 8 b which allows cleaning of the rearsurface of the dust-proof plate 11 and the front surface of thefirst-unit eyepiece lens 27. As a result, it is possible to effectivelyremove foreign matter such as dust adhering to the rear surface of thedust-proof plate 11 and the front surface of the first-unit eyepiecelens 27 without damaging the display module 9.

Further, the dust-proof plate 11 is arranged between the display module9 and the first-unit eyepiece lens 27, so that no external light isallowed to directly impinge upon the dust-proof plate 11. Thus, there isno need for the surface of the dust-proof plate 11 to be provided with acoating for preventing reflection, whereby it is possible to achieve areduction in man-hours and cost.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures, and functions.

This application claims priority from Japanese Patent Application No.2010-187127 filed Aug. 24, 2010, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An imaging apparatus comprising: a displaymodule; a dust-proof plate arranged on an observer side of the displaymodule and configured to substantially seal a surface of the displaymodule; an eyepiece lens arranged on the observer side of the dust-proofplate and movable in an optical axis direction; and a cover memberretaining the dust-proof plate and the eyepiece lens, wherein the covermember has an opening for removing foreign matter adhering to thesurface of the dust-proof plate opposed to the eyepiece lens and to thesurface of the eyepiece lens opposed to the dust-proof plate.
 2. Theimaging apparatus according to claim 1, wherein the cover member retainsa display unit integrating the display module and the dust-proof plateand an eyepiece lens unit integrating a plurality of lenses, and whereinthe opening is formed to allow removal of foreign matter adhering to thesurface of the dust-proof plate opposed to the eyepiece lens and to thesurface of the eyepiece lens unit opposed to the dust-proof plate. 3.The imaging apparatus according to claim 1, wherein the display modulehas a light source, and a film surface configured to reflect light fromthe light source to the image display surface.
 4. The imaging apparatusaccording to claim 1, wherein the imaging apparatus has a detachableeyecup, the opening being covered by attaching the eyecup to the imagingapparatus.